Microfabrication techniques or microelectromechanical systems (MEMS) that have revolutionized the electronics industry are now poised to revolutionize the pharmaceutical and biotechnology industries, and basic biomedical sciences. The two leading applications of microfabrication in biology include "genes-on-a-chip" to monitor the expression level of potentially all genes in humans and organisms simultaneously, and "lab-on-a-chip" type devices to perform high-throughput biochemistry in very small volumes. Equally exciting is the fact that recent advances in the understanding of cellular behavior in microenvironments have started to pave the way towards living micro-devices. The emerging living cell-based devices are expected to become key technologies in the 21st century of medicine with a broad range of applications varying from diagnostic, therapeutics, cell-based high-throughput drug screening tools, and basic and applied cell biology tools. The mission for the proposed NIH BioMEMS Resource Center is to provide unique capabilities to biomedical investigators in order to efficiently use microsystems technologies to probe, perturb, engineer, and analyze biological cells and tissues for basic biological discovery, diagnostic, prognostic, and therapeutic purposes. In order to make the tools of BioMEMS available to the biomedical community, we focused our efforts on 3 core technological research and development projects, Core Project 1 is primarily a technology development proposal with the overall aim of developing microfluidic systems to manipulate and sort blood cells without altering their phenotypes. Core Project 2 advances microfabrication tools to create engineered complex tissue units for dynamic studies of physiological processes. Core Project 3 probes into the molecular and cellular mechanisms of leukocyte bidirectional motility in immune response. The technological research and development program centered around these 3 Core Projects not only involves sound technology development but also addresses important biological problems in leukocyte biology, chemotaxis and immune response, and tissue engineering. In addition, there are 9 collaborative projects that both utilize and help advance the core technologies. The proposed NIH BioMEMS Resource Center will provide services to NIH investigators to use the tools of microsystems technology in biology and medicine. The dissemination activities are very broad encompassing (1) seminars, symposia, and meetings, (2)workshops and courses, and (3) various types of publications. The training activities include both pre-doctoral and post-doctoral (both MD and PhD) fellows, and specialized training sessions to provide hands-on microsystems technology training to biomedical scientists. The proposed NIH BioMEMS Resource Center has already established significant strategic alliances with three other P41 Biotechnology Resource Centers, an NSF Educational Research Center (ERC), an NIH Bioengineering Research Partnership (BRP) grant, and two NIH "Glue Grants". Thus, the proposed Resource Center is exceedingly well poised to disseminate the tools of microfabrication to the biomedical community.